| Index: openssl/doc/crypto/CMS_compress.pod
|
| ===================================================================
|
| --- openssl/doc/crypto/CMS_compress.pod (revision 0)
|
| +++ openssl/doc/crypto/CMS_compress.pod (revision 0)
|
| @@ -0,0 +1,73 @@
|
| +=pod
|
| +
|
| +=head1 NAME
|
| +
|
| +CMS_compress - create a CMS CompressedData structure
|
| +
|
| +=head1 SYNOPSIS
|
| +
|
| + #include <openssl/cms.h>
|
| +
|
| + CMS_ContentInfo *CMS_compress(BIO *in, int comp_nid, unsigned int flags);
|
| +
|
| +=head1 DESCRIPTION
|
| +
|
| +CMS_compress() creates and returns a CMS CompressedData structure. B<comp_nid>
|
| +is the compression algorithm to use or B<NID_undef> to use the default
|
| +algorithm (zlib compression). B<in> is the content to be compressed.
|
| +B<flags> is an optional set of flags.
|
| +
|
| +=head1 NOTES
|
| +
|
| +The only currently supported compression algorithm is zlib using the NID
|
| +NID_zlib_compression.
|
| +
|
| +If zlib support is not compiled into OpenSSL then CMS_compress() will return
|
| +an error.
|
| +
|
| +If the B<CMS_TEXT> flag is set MIME headers for type B<text/plain> are
|
| +prepended to the data.
|
| +
|
| +Normally the supplied content is translated into MIME canonical format (as
|
| +required by the S/MIME specifications) if B<CMS_BINARY> is set no translation
|
| +occurs. This option should be used if the supplied data is in binary format
|
| +otherwise the translation will corrupt it. If B<CMS_BINARY> is set then
|
| +B<CMS_TEXT> is ignored.
|
| +
|
| +If the B<CMS_STREAM> flag is set a partial B<CMS_ContentInfo> structure is
|
| +returned suitable for streaming I/O: no data is read from the BIO B<in>.
|
| +
|
| +The compressed data is included in the CMS_ContentInfo structure, unless
|
| +B<CMS_DETACHED> is set in which case it is omitted. This is rarely used in
|
| +practice and is not supported by SMIME_write_CMS().
|
| +
|
| +=head1 NOTES
|
| +
|
| +If the flag B<CMS_STREAM> is set the returned B<CMS_ContentInfo> structure is
|
| +B<not> complete and outputting its contents via a function that does not
|
| +properly finalize the B<CMS_ContentInfo> structure will give unpredictable
|
| +results.
|
| +
|
| +Several functions including SMIME_write_CMS(), i2d_CMS_bio_stream(),
|
| +PEM_write_bio_CMS_stream() finalize the structure. Alternatively finalization
|
| +can be performed by obtaining the streaming ASN1 B<BIO> directly using
|
| +BIO_new_CMS().
|
| +
|
| +Additional compression parameters such as the zlib compression level cannot
|
| +currently be set.
|
| +
|
| +=head1 RETURN VALUES
|
| +
|
| +CMS_compress() returns either a CMS_ContentInfo structure or NULL if an error
|
| +occurred. The error can be obtained from ERR_get_error(3).
|
| +
|
| +=head1 SEE ALSO
|
| +
|
| +L<ERR_get_error(3)|ERR_get_error(3)>, L<CMS_uncompress(3)|CMS_uncompress(3)>
|
| +
|
| +=head1 HISTORY
|
| +
|
| +CMS_compress() was added to OpenSSL 0.9.8
|
| +The B<CMS_STREAM> flag was first supported in OpenSSL 1.0.0.
|
| +
|
| +=cut
|
|
|